An electro luminescence (hereinafter, abbreviated as “EL”) display device including EL elements using EL of organic materials or inorganic materials, which is an all solid-state type, has self-luminosity, and is excellent in low voltage driving and high responsiveness, has been being developed as a candidate of a next generation display technology.
The EL element is generally formed through film formation by a vacuum vapor deposition technique in which vapor deposition particles (component formed into film) are vapor-deposited on a target film forming substrate via a vapor deposition mask (also referred to as a shadow mask) under a reduced pressure (under a high vacuum), the vapor deposition mask having an opening of a prescribed pattern formed thereon. At this time, as a large substrate film formation technology using a large substrate as a target film forming substrate, a scan vapor deposition technique is promising which does not require a vapor deposition mask or vapor deposition source having a size equivalent to a large target film forming substrate. The scan vapor deposition technique performs scan film formation in which the vapor deposition source smaller than the target film forming substrate, or the vapor deposition mask and vapor deposition source smaller than the target film forming substrate are used to perform film formation while scanning the target film forming substrate.
In the film formation through the vacuum vapor deposition technique, a vapor deposition source including a heating portion and an emitting port is located within a vacuum chamber which is capable of keeping an inside thereof in a reduced pressure state such that the vapor deposition material is heated under a high vacuum to evaporate or sublimate the vapor deposition material. The vapor deposition material heated by the heating portion to be evaporated or sublimated is externally emitted to outside from an emitting port as the vapor deposition particles and deposited on the target film forming substrate.
However, the vapor deposition material heated by the heating portion to be evaporated or sublimated is scattered on an inner wall of the vapor deposition source (i.e., inner wall of a holder housing the heating portion), or the vapor deposition particles repeatedly collide with each other, and after that, the vapor deposition material is emitted from the emitting port.
Such scattering of the vapor deposition particles causes the vapor deposition particles emitted from the emitting port to be emitted in various directions.
In the vacuum vapor deposition technique, the vapor deposition particles emitted toward the target film forming substrate contribute to the film formation, but other vapor deposition particles do not contribute to the film formation. Therefore, in the vacuum vapor deposition technique, the vapor deposition particles other than the vapor deposition film deposited on the target film forming substrate are all loss of the materials. For this reason, the lower a directivity of the vapor deposition particles, the lower a material usage efficiency.
In recent years, a method has been proposed in which a directivity of the vapor deposition particles is heightened by limiting scattering directions of the vapor deposition particles, to thereby lead the vapor deposition particles to a vapor deposition region (e.g., PTL 1 or the like).
PTL 1 discloses that a flow of the vapor deposition particles (vapor deposition flow) is controlled by use of regulation plates regulating coming directions of the vapor deposition particles to improve usage efficiency of the vapor deposition material and improve film formation quality such that uniform vapor deposition is performed.
In a vapor deposition device disclosed in PTL 1, a target film forming substrate to be subjected to vapor deposition and a vapor deposition source are located within a vacuum chamber, and the vapor deposition particles discharged from the vapor deposition source are made to deposit on the target film forming substrate to form a vapor deposition film, not illustrated, on the target film forming substrate.
The vapor deposition source disclosed in PTL 1 includes three layered frame structures. A heating coil is wound around these frame structures.
The bottom frame structure is a heating portion (vapor deposition particles generation portion) which accommodates and heats the vapor deposition material to generate the vapor deposition particles. Each of the other two frame structures is a vapor deposition flow regulating layer (vapor deposition flow controller) which regulates directions of the vapor deposition particles from the bottom frame structure as the heating portion toward the target film forming substrate.
In the above two frame structures used as the vapor deposition flow regulating layer, there are formed multiple nozzle-like passing zones (vapor deposition nozzle, emitting port) sectioned by the regulation plates which are provided along the directions from the bottom frame structure used as the heating portion toward the target film forming substrate.
With this configuration, the scattering directions of the vapor deposition particles discharged from the heating portion via the respective passing zones are regulated to a direction along lateral surfaces of the respective regulation plates in the passing zones.